That’s a very lenient policy.
Microsoft have changed their policies for Gamertag retention on Xbox Live a bit– users will now be required to log into their Xbox Live account once every five years if they want to retain their Gamertags. If you fail to log in at least once in a five year period, your Gamertag could be retired and made available to other users. However, your purchases and Microsoft account will remain secure.
That said, it shouldn’t be too hard for users to manage to log in at least once every five years- after all, you can log into Xbox Live via the web, or using the Xbox apps on iOS, Android, and Windows Phones, as well as on PCs and tablets running Windows 10. If after all of this you somehow manage to not log in, then honestly, you probably don’t care enough about your Xbox Live to begin with- in which case, you probably shouldn’t care that you lost your Gamertag.
The changes will come into effect starting September 15.